How Much Difference Do High Octane Fuels Make To Power Outputs?
In this segment the Fifth Gear lot have plucked from their archives, Vicki Butler Henderson investigates "posh petrols" to see how much of a difference they can make to power outputs
To find out more about the differences between high and low octane fuels, check out our guide from Engineering Explained.
Growing up on a diet of World Rally Championship highlights and lengthy Gran Turismo 2 sessions, a life in cars was as good as inevitable for Matt.
Comments
What she failed to mention though is the premium fuels are generally better for the health of the engine, but either way they are not worth the price
Your car is an extension of your body. If you like eating free range organic products, then you should be filling up your car with premium fuel.
What if you up the timing and only run on high octane fuel?
Ok, so they might be pricey. Bu i have a 1.25 2001 ford fiesta (I know, nothing to shout about). but when I run it on standard fuel at lower revs, I can hear it pre-igniting, esp when driving with a tall wall next to me. but when I used super unleaded. it doesn’t pre-ignite. and you can feel the difference in responsiveness lower in the rev range. but I only use it when I feel like giving my car a little treat :)
COBB tuning will probably disagree as with other tuners of Turbocharged cars…
Sure a stock car is designed to perform similarly with different octane levels but once you tune, 93AKI/98RON has a ton of benefits over 91AKI/95RON.
And then there’s AKI and RON… No, ‘Muricans don’t always get poor gas… Unless they are in California.
I’m sure they also tried this a long time ago with a Clio, a Subaru, and a Golf. The Subaru got the most benefit from the premium fuel because it’s a higher compression, performance based engine. It’s all to do with compression and how much stress the engine will be put under, it’s the same reason why some tuners put flex fuel systems in and run on Ethanol. However, some fuels will have cleaning agents inside, giving a benefit regardless. I dunno, as long as my Polo and my van can run on it, it’s good to me. Not like they’re going to run any track days soon.
All cars in the UK have to be able to run on 95 RON fuel. However if you had a more hardcore car than the GTi I’m sure there would be a greater difference. A subaru impretza was given some posh fuel and it was up more than 15 BHP
https://www.youtube.com/watch?v=gQghB4asSnI
You can see why this show is so unpopular… Firstly, an engine designed for 98 (golf is 95) will make a bigger difference.. Furthermore, running crappy fuel on a car designed for 98 will increase the wear n tear n lower the reliability of the engine
Only makes a real difference under high compression ratio/high boost circumstances. The higher the octane rating, the less likely to pre-ignite.
I would like someone to test range per tank rather than horsepower, my old car was a 2007 ford falcon 4L straight six, when ran on 91ron would be lucky to get 650kms to a tank, when ran on 98 regularly got 850+ out of a tank, that’s more money in your pocket if the price isn’t too over the top, on average was an extra 12 cents for 98 where I filled up